Add the delay when doing set_gain or power_up

HX711.cpp

@@ -7,11 +7,13 @@
     void yield(void) {};
 #endif
 
-HX711::HX711(byte dout, byte pd_sck, byte gain) {
+HX711::HX711(byte dout, byte pd_sck, byte gain) :
+		OFFSET(0), SCALE(1.0) {
 	begin(dout, pd_sck, gain);
 }
 
-HX711::HX711() {
+HX711::HX711() :
+		GAIN(1), PD_SCK(-1), DOUT(-1), OFFSET(0), SCALE(1.0) {
 }
 
 HX711::~HX711() {
@@ -45,7 +47,7 @@ void HX711::set_gain(byte gain) {
 	}
 
 	digitalWrite(PD_SCK, LOW);
-	read();
+	read_average(1 + 6); //6 times is invalid.
 }
 
 long HX711::read() {
@@ -95,16 +97,16 @@ long HX711::read_average(byte times) {
 	return sum / times;
 }
 
-double HX711::get_value(byte times) {
+long HX711::get_value(byte times) {
 	return read_average(times) - OFFSET;
 }
 
 float HX711::get_units(byte times) {
-	return get_value(times) / SCALE;
+	return (float) get_value(times) / SCALE;
 }
 
 void HX711::tare(byte times) {
-	double sum = read_average(times);
+	long sum = read_average(times);
 	set_offset(sum);
 }
 
@@ -130,5 +132,9 @@ void HX711::power_down() {
 }
 
 void HX711::power_up() {
+	long dump = 0;
 	digitalWrite(PD_SCK, LOW);
+	//When power up, default gain is 128, channel A.
+	//rate is 10Hz, so 400ms is 5 times.
+	dump = read_average(6); //5 times is invalid.
 }

HX711.h

@@ -13,8 +13,8 @@ class HX711
 		byte PD_SCK;	// Power Down and Serial Clock Input Pin
 		byte DOUT;		// Serial Data Output Pin
 		byte GAIN;		// amplification factor
-		long OFFSET = 0;	// used for tare weight
-		float SCALE = 1;	// used to return weight in grams, kg, ounces, whatever
+		long OFFSET;	        // used for tare weight
+		float SCALE;    	// used to return weight in grams, kg, ounces, whatever
 
 	public:
 		// define clock and data pin, channel, and gain factor
@@ -46,7 +46,7 @@ class HX711
 		long read_average(byte times = 10);
 
 		// returns (read_average() - OFFSET), that is the current value without the tare weight; times = how many readings to do
-		double get_value(byte times = 1);
+		long get_value(byte times = 1);
 
 		// returns get_value() divided by SCALE, that is the raw value divided by a value obtained via calibration
 		// times = how many readings to do

examples/HX711SerialDemo/HX711SerialDemo.ino

@@ -0,0 +1,107 @@
+#include "HX711.h"
+
+HX711 scale;
+void loop_test_hx711() {
+	int which = 0;
+  uint32_t preMillis = 0L;
+	while (which < 5) {
+		//Power cycle takes around 400ms so only do so if our test rate is greater than 500ms
+		if ((millis() - preMillis) >= 5000) {
+			switch (which) {
+				case 0:
+				case 2:
+				case 4:
+					scale.power_down();
+					Serial.print(F("powerDownScale\n"));
+					delay(1000);
+					Serial.print(F("powerUpScale\n"));
+					scale.power_up();
+				break;
+				case 1:
+					scale.set_gain(128);
+					Serial.print(F("set_gain=128\n"));
+				break;
+				case 3:
+					scale.set_gain(64);
+					Serial.print(F("set_gain=64\n"));
+				break;
+				default:
+					which = 0;
+				break;
+			}
+			preMillis = millis();
+			which++;
+		}
+
+		float currentReading = 0;
+		//Print raw reading
+		long rawReading = scale.read();
+		Serial.print(millis());
+		Serial.print(F(","));
+		Serial.print(rawReading, HEX);
+		Serial.print(F(",\t"));
+		//Take average of readings with calibration and tare taken into account
+		currentReading = scale.get_units(1);
+		Serial.print(millis());
+		Serial.print(F(","));
+		//Print calibrated reading
+		Serial.print(currentReading, 3);
+		Serial.println();
+	}
+	Serial.println(F("Loop test is done!"));
+}
+void setup() {
+  Serial.begin(38400);
+  Serial.println("HX711 Demo");
+  Serial.println("Initializing the scale");
+  // parameter "gain" is ommited; the default value 128 is used by the library
+  // HX711.DOUT	- pin #A1
+  // HX711.PD_SCK	- pin #A0
+  scale.begin(A1, A0);
+	loop_test_hx711();
+
+  Serial.println("Before setting up the scale:");
+  Serial.print("read: \t\t");
+  Serial.println(scale.read());			// print a raw reading from the ADC
+
+  Serial.print("read average: \t\t");
+  Serial.println(scale.read_average(20));  	// print the average of 20 readings from the ADC
+
+  Serial.print("get value: \t\t");
+  Serial.println(scale.get_value(5));		// print the average of 5 readings from the ADC minus the tare weight (not set yet)
+
+  Serial.print("get units: \t\t");
+  Serial.println(scale.get_units(5), 1);	// print the average of 5 readings from the ADC minus tare weight (not set) divided 
+						// by the SCALE parameter (not set yet)  
+
+  scale.set_scale(2280.f);                      // this value is obtained by calibrating the scale with known weights; see the README for details
+  scale.tare();				        // reset the scale to 0
+
+  Serial.println("After setting up the scale:");
+
+  Serial.print("read: \t\t");
+  Serial.println(scale.read());                 // print a raw reading from the ADC
+
+  Serial.print("read average: \t\t");
+  Serial.println(scale.read_average(20));       // print the average of 20 readings from the ADC
+
+  Serial.print("get value: \t\t");
+  Serial.println(scale.get_value(5));		// print the average of 5 readings from the ADC minus the tare weight, set with tare()
+
+  Serial.print("get units: \t\t");
+  Serial.println(scale.get_units(5), 1);        // print the average of 5 readings from the ADC minus tare weight, divided 
+						// by the SCALE parameter set with set_scale
+
+  Serial.println("Readings:");
+}
+
+void loop() {
+  Serial.print("one reading:\t");
+  Serial.print(scale.get_units(), 1);
+  Serial.print("\t| average:\t");
+  Serial.println(scale.get_units(10), 1);
+
+  scale.power_down();			        // put the ADC in sleep mode
+  delay(5000);
+  scale.power_up();
+}